Electrochemical Properties of Hydroxyapatite Crystal Surfaces on Anatase Photocatalysts

Hydroxyapatite (HAp) was crystallized on anatase titanium dioxide (TiO 2 ) photocatalytic crystals or their thin films using of a pseudo‐body solution method, and electrochemical properties of the HAp‐adhered anatase TiO 2 photocatalytic surfaces were discussed. Decomposition rates of methylene blue were faster for the HAp‐adhered anatase TiO 2 photocatalysts, although specific surface areas were smaller than those for the commercial anatase TiO 2 ones. Surface potential dispersions on the HAp‐adhered anatase TiO 2 thin films before and after an ultraviolet light irradiation were measured by an atomic force microscopy. Changes in the color of leucocrystalviolet mixed in the HAp‐adhered anatase TiO 2 photocatalysts or the commercial anatase TiO 2 ones with experimental durations were compared. Movements of electrons from the anatase TiO 2 photocatalytic surfaces to the HAp, crystals and oxidizing reactions on the HAp‐adhered anatase TiO 2 photocatalytic surfaces in the dark were discussed on the basis of these experimental results.